Short answers, pulled from the story.
The German Luftwaffe began its unrestricted aerial bombardment of Warsaw on the 1st of September 1939. This campaign targeted both military facilities and civilian infrastructure.
Hermann Göring controlled the air force operations that day. Pilots attacked infantry barracks, the Okęcie airport, and an aircraft factory while also striking water works, hospitals, market places, and schools.
The Pursuit Brigade lost over 38 pieces of equipment by September 7 which represented approximately 70% of their initial strength. Most planes were obsolete PZL P.7 or PZL P.11 types before these losses occurred.
Around 18,000 civilians perished during the siege of Warsaw. Ten percent of city buildings were entirely destroyed while further 40% were heavily damaged.
At 12:00 on September 27, a ceasefire agreement was signed halting all fighting. Soon afterwards Warsaw officially capitulated and evacuation of Polish forces to prisoner camps started on September 30.